Spark plug



INVENTOR Oct. 26, 1926.

E. J. RUBERT l SPARK PLUG Filed Dec.' 28. 1925 i f 'l n ldatented @et E), 1

EMXL J'. RUBERT, OF EI'ITSBURGH, EENNSYLVANIA.

SFARK PLUG.

Application led December 2S, 1925. Serial No. 78,041.

This invent-ion relates to spark plugs for lltis a further special object ot the invenuse in connection with internal combustion tion to provide a plug especially adapted motors. tor long continued service. without fouling lt an object ot the invention to provino in niotors ot the coil-puni'oeim class, by c0- 5 salt-cleaning plugwhich is extremely ordinating; the parts whereby to divide the simple in construction. economical to tabrientire space disposed between the encirclcate, .viich can be easily assembled and dis ing; ins-urlatina body oit the usual central numbered, which positive in its action, electrode and the niain body oi the plug` which will not readily v.eet out of order, and into a pair ot conoentrically arranged oom- ]0 'which is entrernelyV durable and highly partnients or chambers by means ot a tubuetlcient in operation. removable outer electrode7 and to so 65 lt is aV special obiect to provide a plug; of construct the saine that a cleaningv blast will this character havinn a bouily removable be autom 'cally directed through both ot tubular electrode niade ot a non-oorrodible these coin aartinents and `throughout sub- 15 material so coordinated with the inain stantially their entire extents during the body ot the plusthat it will be securely irinp; of the motorT whereby to remove anchored .in position upon the assembly of 'foreign substances which would otherwise the several parts with a tree annular space collect thereinn and ultimately result in the disposed-both at the exterior and interior 'fouling ot the plug.

20 oi the electrode and between the rnain body A. still further object is to provide a and insulating' body ot the inner central plus' including` a removable tubular elec- 75 electrode, respectively. trede having); an unbroken tree lower end Another special object is to provide a and unbroken portions extending' through,-

plun; having`v a bodily rernovable tubular out the entire length oi its tubular wall electrode whereby by constructing said whereby to etl'ectively withstand without electrode in a variety oit lengths and selectdanger oi iniury not only to blows ot sutil ingr the inost appropriate length oit eleecient strength to remove the electrode, even trede the plu@ can be ellicentlv aCCominoin cases of sticking-1 but which will positivedated to diilerent makes and types ot ly ,eguard the sparking points ot the plug 30 motors, and one in which a detective elecagainst damage it roughly handled or aocitrode may be quickly and easily replaced dentally dropped. S5 with a new one., should occasion demand. An additional special object is to so posi- Heretmtore.y ,e'reat diiiioulty has been eX- tion the sparking portions ot the tubular perienced with plugs commonly tound upon electrode that they will gew@ t@ Daytially the inarlret due to the fouling` thereot` momentarily coniine the combustible gases brought about by the accumulation ot soot., within the interior ot the electrode at the carbon and other foreign matter.y resulting time oi the tiring; ot the charge for the purtroni the combustion within the tiring` poso, or' initiating; a. VHow outwardly through chamber7 between the porcelain body enarcuate conducting' slits provided in the circling' the inner el Vctrode and the niain wall ot the electrode towards the compartbody of the pluri. Such elieet iS Dil-350W ment surrounding` the sa. e whereby to larly harmful when these foreign substances cause a swirling` action therein7 and at the collect around the said porcelain body time serve as a means tor catchingand adjacent the region at which it is seated retaininnvparts ot tl e insulating` porcelain within the inn/in body. This accumulation body surrounding` the inner electrode should is most pronounced in engines or motors ot it become broken. the ,so-called oil-puniper type7 or those in- These and other objects ot the invention which an eXcesSive quantity' of lUlOICaHt will more fully appear when taken in conilinds its way into the combustion chambers. junction with the followingdescription and ln tact, with plugs: now in common use, it the appended olainis. is practically impossible to operate such In tho aceoinpanyinedrawings forining motors any substantial length ot time withf a part ot the application. 1 is view, (uit 'fouling the DlugS t0 il. point where they partially in elevation and partially in Velu l'ieoonie utterly unlit ttor practical service. tical section, illustrating the preferred einbodinient of the invention; Fig. 2 an elevational view of the outer tubular electrode; and Figi'. 3 a bottom plan view oit the tubular electrode showingl how the sparking,Y points or portions are formed thereon.

Referring to the drawings, l desigijnates the main body of the plug,` whicn is tuluila in form, having' a bore extending completely therethrough. IThe lower end ot the body is slightly reduced in size and exteriorly threaded at 2 for threading' into the usual openings provided for vthis purpose in the motor casting. The bore of the main body is interiorly threaded adjacent its upper end as at 3, and is provided at a point intermediate its length with a rib il which projects radially inwards, the upper tace ot the rib providingl a tapered shoulder orseat 5 upon which the outer tubular electrode, to be subsequent-ly described, rests and which serves as an abutn'ient iior positioning` the inner electrode relatively to the remaining parts. The lower face oit the rib il is under-cut in the fashion clearly indicated in Fig'. l, providing` an over-hanging tapered ledge which assists in del'lecting the llow of gases employed for cleaning purposes in the desired direction.

rlhe inner, or centrally disposed electrode corresponds to a type now connnonly liound in various plugs upon the market and includes an encircling body of insulating` inaterial 7, preferably porcelain, having,Y an enlarged intermediate portion 7 and a lower tapered extremity 7, the latter terminatingshort ot the protrudimij lower end 8 oit the electrode proper.

The remaining, or outer electrode, is designated generally at 9, and is in the ioriu of a bodily removable tubular element ot substantially cylindrical shape with its upper extremity lO flared outwardly in the form oit a bell. The lower end ol the tubular electrode 9 is plain, having an unbroken or uninterrupted end iace il, while its tabular wall is also equipped with unbroken or uninterrupted portions which extend conipletely from the lower end tace ll to its upper llared extremity lO. tubular wall of the electrode 9 is d with slits l2, l2 at points spaced 'from the end 'tace l1, and the metal thereof immediately below and adjacent these slits is turned inwardly in the fashion clearly shown in Fig. 8 to provide the sparkingpoints or j tions 13, 18, respectively. The tubular wall et the electrode 9 is also equipped with a pair et arcuate-shaped slits lll, lll, both ends of which terminate short ot the extremities of the electrode, and are so disposed relatively to the remaining parts thereoiE as to leave the unbroken portions extending throughout the entire lengi'th oit the electrode, as previously described.

The outer diameter oliI the tubular elec- Leon-lea trode throughout its cylindrical portion, immediately below the flared extremity l0, corresponds substantially with the diameter ol" the reduced opening delined by the rib l, whereby to provide a neat lit ot the electrode i) therein when placed in operative position with the parts oi the plug' assembled, as illustrated in 2. Although the electrode 9 may be made olf any metal suitable 'or the purpose, it is contemplated making the same of a highly conductive non-corrodible metal such as copper or Monel metal.

rJhe over-all length of the electrode 9 is preferably slightly greater than the distance from the shoulder 5 to the lower open end of the main body oi" the plug, so that it projects slightly below the said main body.

ln assembling' the several parts, the electrode 9 is inserted within the bere ot the main bony with the cylindrical portion thercolE projecting,- downwardly through the restricted opening formed by the rib -l-, and with its upper flared extremity l0 seating' directly upon the shoulder 5. rlhe inner electrode is then positioned with its enlarged portion 7 superposed upon the upper extremity ot the tubular electrode preterably with a washer 15 interposed therebetween, and is locked into gripping` renution therewith by means ot a gland nut 16 threadedly engaging the portion 3 ot the main body, and adapted to eng-'afge the upper part of the enlarged portion 7.

`With the parts thus assembled, the snug' engagement of the cylindrical wall ot the electrode 9 with the opening' 'termed by the rib ,4, together with the intimate engagement el the washer and the insulating body ot the inner central electrode, the several parts are held rigidly in the lined relative positions shown in Fig. 2 of the application drawings.

lilith the several parts positioned relatively, as described, the tubular electrode 9 provides a space between the insulating' body oli the inner electrode and the main body of the pluginto two concentrically arranged chambers or compartments 1G, 1". the compartment 1G being, located around the lower tapered Vportion 27 of the inner electrode, and extending from a point adjacent the uflared extremity l() oit the outer electrode waile the compartment 1G extends from 'overhanging ledge G to the lower end of the main body olf he plus. lt is noted that the arcuate fluid conducting slits or passages l-l, lei extend to a region ailjacent the upper portions ot both ot these compartments. lt is also pointed out that due to the bending; of the metal radially inwards to form the sparlrine' points or portions ll, 13, at the same time etlects a partial closure of the lower end ot the tubular electrode which is adapted to function not only as a means for partially and momentarily restricting the i'low ot gases downwardly through the lower end ot the electrode during the :firing of the motor, but functions also a means for catching and retaining` portions oi the insulating` body of the inner electrode should the saine become broken, thus preventing such broken portions falling directly into the iii-ing chamber and giving rise to trouble 'troni this source. rlhe bending inwardly ot the metal immediately below the slits l2, 12, in addition, serves an eii'ective guard against injury to the lower extremity 8 ot the inner electrode, due to rougfrh handling or accidental dropping ot the plug.

ln use, with the several parts asscmbleifl as shown in lEig. 2 oit the drawiu the plug is bodily screw-d intothe threader. c j provi( ed on the motor c .sting for pose, as is the usual practi/e intake and Compression strokes ot tee in a portion ot the combustilre ch:` way into the chambers or coinpar lo. Upon the tiring ot the motor, the sparking gap being` located between the projecting portion 8 ot the inner electrode and the apexes ot the portions 123, 13", as is obvious, due to the partial` restriction afforded by the inwardly bent portions at the lower end ot the tubular electrode, a tlow of the is initiated radially outwards through the arcuate passages or slits ill, 14], trom the conipartment 16 towards the compartment 16. Such ilow of gases is produced periodically duringl each ot the iiringistrokes ot the motor. By extending the passages 141i, lll. to a point adjacent the upper regions et the compartments 16, 1G', all soot, burnt carbon, and other 'for eign substances, are effectively removed from these spaces, and the several parts maintained in a clean condition conducive to the proper tiring` ot the plug. rlhe provision ot the overhanging ledge 6 enhances the benelicial eilect incident to the flow of gases thus initiated, in that the inclined face thereoit serves to deflect the gases towards the body ot the plug and to assist in ultimately diverting` the path of travel thereot downwardly through the comjiartment 16.

i ttent-ion is directed to the 'tact thatthe entire outer tubular electrode 9 is an intogral unitary construction providingan extremely sturdy and ru 'ged structure. Because ot this, the plug is capable of withstanding severe usage without danger of dcrangement ot the sparking points 13, i3. and the continuous end tace 1l toejether with the unbroken portions ot the side wall mtendin qcompletely throughout its length afford a means oit forcibly ren'ioving` the electrode by tapping upon its lower tree end with a suitable tool. should such recourse become necessary. The desirability ot the trode is disposed immediately opposite the portions 13, 13 ot the outer electrode, as shown in llio. 2. Should the tip 8 become shortened due to prolonged use, it may be easily repositioned so as to assume a proper relative position with respect to remaining parts by merely removing the washer 15 and seating the portion 'l' directly upon the ila-red terminal l0.

l claim:

l. A spark plug for internal combustion motors comprising a. main body provided with a bore open at its lower end, an inner electrode having an encircling body ot insulating material anchored within the main body and projecting` downwardly into said bore thereof, an outer removable tubular electrode interposed between the said insulating body and said main body dividing` the space therebetween into two annular compartments, the wall of said tubular electrode having fluid conducting passages formed therein said passages extending to a point adjacent the upper region of the said compartments.

2. A spark plug for internal combustion motors comprising a main body provided with a bore open at its lower end, an inner electrode having an encircling body of insulating material anchored within the main body and projecting downwardly into said bore thereof,l an outer removable tubular electrode interposed between the said insulating body and said main body dividing the space therebetween into two annular compartments, the wall of said tubular electrode having iluid conducting slits termed therein, the said slits stopping short ot the lower extremity ot the tubular electrode and extending to a point adjacent the upper region ot the said compartments.

3. A spark plug for internal combustion motors comprising a main body provided with a bore open at its lower end, an inner electrode having an encircling body of insulating material anchored within the main body and projecting downwardly into said bore thereof, an outer removable tubular electrode interposed between the said insulating` body and said main body dividing the space therebetween into two annular compartments, the wall of said tubular electrode having iiuid conducting slits formed therein, said slits being ot' arcuate shape whereby to produce a swirling ot the fluid passing therethrough, and extending to a point adjacent the upper region of the said compartments.

A spark plug for internal combustion motors comprising a main body provided with a central bore, said body having an inwardly extending rib forming a seat at one side thereof, an inner electrode having` an encircling body of insulating material projectin(y downwardly towards the lower open end of the bore of the main body, an outer tubular electrode gripped between the said insulating body and the said seat and extending downwardly towards the lower open end of the bore of the main body, said tubular electrode being spaced below the said seat from the said insulating body and below the said rib from the said main body, the wall ot the said tubular electrode having iluid conducting passages formed therein coeiitensive with the space between the electrode and said main body for conducting 'Huid from the space within the interior of the electrode to the space surrounding the same.

5. il spark plug for internal combustion motors comprising a main tubular body, a centrally disposed inner electrode having an encircling` body ot insulating material anchored in the main body and projecting downwardly therein towards its lower open end, the said insulating body terminating short of the lower extremity of the inner electrode, an outer tubular electrode interposed between said insulating and main bodies dividing the space therebetween into a pair ot compartments and extending below the said insulating body, said tubular electrode being slit at a point spaced irom its lower extremity and bent radially inwards adjacent thereto to i'orm sparking tips, and being further provided with luid conducting passages establishing communication between 'the said compartments, said passages being coextensive with the outer compartment and adapted to discharge gases adjacent the upper regions of the said compartments.

In testimony whereof, I sign my name.

EMIL d'. RUBERT. 

